Combined eye activity measures accurately estimate changes in sustained visual task performance

Citation
Kf. Van Orden et al., Combined eye activity measures accurately estimate changes in sustained visual task performance, BIOL PSYCH, 52(3), 2000, pp. 221-240
Citations number
20
Categorie Soggetti
Psycology
Journal title
BIOLOGICAL PSYCHOLOGY
ISSN journal
03010511 → ACNP
Volume
52
Issue
3
Year of publication
2000
Pages
221 - 240
Database
ISI
SICI code
0301-0511(200004)52:3<221:CEAMAE>2.0.ZU;2-4
Abstract
Five concurrent eye activity measures were used to model fatigue-related ch anges in performance during a visual compensatory tracking task. Nine parti cipants demonstrated considerable variations in performance level during tw o 53-min testing sessions in which continuous video-based eye activity meas ures were obtained. Using a trackball, participants were required to maneuv er a target disk (destabilized by pseudorandom wind forces) within the cent er of an annulus on a CRT display. Mean tracking performance as a function of time across 18 sessions demonstrated a monotonic increase in error from 0 to 11 min, and a performance plateau thereafter. Individual performance f luctuated widely around this trend - with an average root mean square (RMS) error of 2.3 disk radii. For each participant, moving estimates of blink d uration and frequency, fixation dwell time and frequency, and mean pupil di ameter were analyzed using non-linear regression and artificial neural netw ork techniques. Individual models were derived using eye and performance da ta from one session and cross-validated on data from a second session run o n a different day. A general regression model (based only on fixation dwell time and frequency) trained on data from both sessions from all participan ts produced a correlation of estimated to actual tracking performance of R = 0.68 and an RMS error of 1.55 (S.D. = 0.26) disk radii. Individual non-li near regression models containing a general linear model term produced the cross-session correlations of estimated to actual tracking performance or R = 0.67. individualized neural network models derived from the data of both experimental sessions produced the lowest RMS error (mean = 1.23 disk radi i. S.D. = 0.13) and highest correlation (R = 0.82) between eye activity-bas ed estimates and actual tracking performance. Results suggest that informat ion from multiple eye measures may be combined to produce accurate individu alized real-time estimates of sub-minute scale performance changes during s ustained tasks. (C) 2000 Published by Elsevier Science B.V.